The frequency or amount at which a thing or things occur within a given area or the set of probabilities that a variable will have a particular value.

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1answer
51 views

Is there a way to create a presence/absence matrix of polygons per cell in a grid using qGIS?

I'm working in QGIS with species distribution polygons and I want to know how many cells in a grid does the polygon overlap. I've tried creating random points within the polygon and then used ...
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0answers
39 views

Maxent Probabilities Values

I am working on my first experiment with Maxent. I am using two different species. When I receive the output map and look at it in QGIS the values for suitable habitat probability do not sum to 1. ...
2
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0answers
94 views

Risk and vulnerability analysis for the spread of alien species

Based on knowledge about the potential for proliferation of alien forests species we are looking at possibilities for modelling the process. Inputs should be area for initial plants, wind, elevation, ...
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1answer
77 views

Is there a way to create an urban extent/population distribution map which only includes areas with a population above 100,000

I'm looking to do analysis on cities throughout the world. I'm using WorldPop, LandScan and MODIS data to gain urban extent and population density maps. I would like to extract areas which have a ...
3
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2answers
67 views

How to create a realistic distribution of cities?

I'm not sure if this is the right community to ask this, so let me know if it's not. I'm wondering if there's been some empirical research as to how villages and cities are distributed around other ...
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0answers
48 views

Redistribution of polygons: supplementing and filling the specific area with polygons with specific size

I'm studying the impact of green wedges (red outline on the figure) on weather parameters in Copenhagen area. What I want to do is check how spatial redistribution of future afforested areas enacted ...
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2answers
785 views

Creating species distribution map?

I have to create some species distribution maps, but I have very little experience with ArcGIS unfortunately. I have two different kinds of excel sheets: 1) A version with many thousand X and Y ...
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1answer
84 views

is there an operation for measuring constancy (ecology)

I'm looking for an effective way to measure changes in spatial location in a time series data set (whether an observation repeats in the same location between successive time-steps, or if it shifts ...
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0answers
64 views

Distribution of POI query result

There are a lot of POIS in the database with fileds id name address lon lat. When we tried to query some points for a given bounding box, it is simple to build the accordingly sql and get the ...
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2answers
47 views

How to see whether a set of postcodes have a typical distribution to the whole postcode population of UK?

For my dissertation I have a dataset of postcodes of 9984 that I am converting to coordinates atm. I looking to find whether this dataset has a 'typical or 'atypical' spatial distribution compared ...
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2answers
352 views

How to get an indication of how points are spatially distributed?

Let's say I have a set of points and I want to get an indication of their spatial distribution. That is, if all points are at one location a possible return value would be 0, whereas if all points are ...
4
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1answer
204 views

Simple way to compare ranges and distributions of species, looking for correlation and differences between ranges

As a biology student just beginning with GIS, wondered if someone could give me an idea of what tools to go about using to compare the range of 3 species that have trophic effects on one another. I ...
3
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1answer
178 views

Re-Distributing Python Toolbox

After reading this Esri article on how to distribute Python Toolboxes, I'm wondering how redistribution works? I have a few toolboxes that are in constant development, but would be useful to my ...
3
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0answers
308 views

Empirical Bayesian kriging - does data need to be normal?

With empirical Bayesian kriging (ebk), does the data need to be normally distributed? If I apply a normal score transformation, my data is still not normal. Is ebk kriging thus an invalid ...
2
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0answers
61 views

Distribute population to health facilities (GP Practices)

I have been using GIS (ArcGis) for some years but I do not consider myself an expert. I am performing some analysis around GP Practices in London (UK), I would like to be able to estimate the ...
2
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2answers
75 views

Where to deposit global coverage dataset?

Some years ago I published a paper on Quarter Degree Grid Cells in the African Journal of Ecology. Quarter Degree Grid Cells (QDGC or QDS – Quarter degree Squares) is a way of dividing the longitude ...